Vitamin B12


Vitamin B12, also called cobalamin, is a water-soluble vitamin that plays a key role in the functioning of the brain and nervous system, the formation of blood, cellular metabolism, DNA synthesis and regulation, fatty acid synthesis and energy production.  

The B12 required for human health has to come from bacteria since fungi, plants, and animals are not capable of synthesizing it. B-12 is also unusual in that it’s absorption depends upon the presence of another substance called intrinsic factor.  Intrinsic factor is a protein secreted by the stomach; without enough intrinsic factor, Vitamin B12 cannot be absorbed into our bodies.

Healthy adolescents and adults need about 2 mcg of cobalamin daily.  Women who are pregnant or lactating need a little more, while children need much less – the amounts range from 0.7 – 1.3 mcg/day depending on the age of the child.

People who might have a greater than average need for cobalamin include those who have:

  • alcoholism
  • depression
  • pernicious anemia
  • Inflammatory Bowel Disease
  • neuropathy

Serious drug interactions exist with:

  • chloramphenicol
  • cobalt irradiation
  • colchicine
  • H2 blockers (such as Tagamet, Zantac, Axid, and Pepcid)
  • proton pump inhibitors (such as Nexium, Prilosec, Losec, Prevacid and Pantaloc)
  • epilepsy medications

No significant interactions have been found with other supplements, botanicals or food.

If you are concerned about your B12 level, please discuss the advisability of B12 supplementation with an MD, ND or pharmacist.

Since animals concentrate Vitamin B12 in their bodies to a much greater extent than do plants, animal food sources are the best: sardines, salmon, shrimps, scallops, lamb, beef, yogurt and eggs.